Sec. 1.003. INTERNAL REFERENCES. In this code: (1) a reference to a title, chapter, or section without further identification is a reference to a title, chapter, or section of this code; and (2) a reference to a subtitle, subchapter, subsection, subdivision, paragraph, or other numbered or lettered unit without further identification is a reference to a unit of the next larger unit of this code in which the reference appears. Acts 1987, 70th Leg., ch. 149, Sec. 1, eff. Sept. 1, 1987.